The main thrust of our research efforts in the 4-1-74 to 3-31-75 period outlined in this proposal will be a continuation of studies of pepsin and the potential digestive power of gastric juices of several common laboratory animals. In the past year a succession of papers directed at this query have been published or are already in press. Our laboratory with 4 years of continuous application has definitely established that an excised and reimplanted stomach is neither apeptic nor achlorhydric, though the responses to both types of secretory stimuli do exhibit persistent quantitative reductions. The greater potential digestive power of human gastric juice over that of all common laboratory animals, save the rabbit, also has been definitely established. The greater susceptibility of fat to infection over that of blood and plasma has been shown. The differences are considerable and persist even attending antibiotic administration. Work has continued with high and low molecular weight fractions of peritoneal fluid, separated by column chromatography, attending arterial mesenteric occlusion to long and short segments of small intestine. We have observed suggestions that life can be prolonged attending hemodialysis, an occurrence that lends credence to the belief that when combined with timely surgery, some salvage of life may be anticipated in an otherwise hopeless situation.